4, 8, 12, 16, 20.
find the mean of the distribution.

The physical processes that create most of earth's physical features, including mountains, are known as

The covers all of earth like a thin shell,but it is not a solid sheet of material.it is broken up into several large sections and many smaller ones. fill in the blank.

Countries that have a traditional economy often develop at a slower pace than countries with a free market economy. true or false